diff --git a/nova/tests/functional/regressions/test_bug_1951656.py b/nova/tests/functional/regressions/test_bug_1951656.py
new file mode 100644
index 00000000000..d705ff6fe31
--- /dev/null
+++ b/nova/tests/functional/regressions/test_bug_1951656.py
@@ -0,0 +1,73 @@
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+from oslo_utils import uuidutils
+
+
+from nova.tests.fixtures import libvirt as fakelibvirt
+from nova.tests.functional.libvirt import test_vgpu
+from nova.virt.libvirt import utils as libvirt_utils
+
+
+class VGPUTestsLibvirt7_7(test_vgpu.VGPUTestBase):
+
+ def _create_mdev(self, physical_device, mdev_type, uuid=None):
+ # We need to fake the newly created sysfs object by adding a new
+ # FakeMdevDevice in the existing persisted Connection object so
+ # when asking to get the existing mdevs, we would see it.
+ if not uuid:
+ uuid = uuidutils.generate_uuid()
+ mdev_name = libvirt_utils.mdev_uuid2name(uuid)
+ libvirt_parent = self.pci2libvirt_address(physical_device)
+
+ # Libvirt 7.7 now creates mdevs with a parent_addr suffix.
+ new_mdev_name = '_'.join([mdev_name, libvirt_parent])
+
+ # Here, we get the right compute thanks by the self.current_host that
+ # was modified just before
+ connection = self.computes[
+ self._current_host].driver._host.get_connection()
+ connection.mdev_info.devices.update(
+ {mdev_name: fakelibvirt.FakeMdevDevice(dev_name=new_mdev_name,
+ type_id=mdev_type,
+ parent=libvirt_parent)})
+ return uuid
+
+ def setUp(self):
+ super(VGPUTestsLibvirt7_7, self).setUp()
+ extra_spec = {"resources:VGPU": "1"}
+ self.flavor = self._create_flavor(extra_spec=extra_spec)
+
+ # Start compute1 supporting only nvidia-11
+ self.flags(
+ enabled_mdev_types=fakelibvirt.NVIDIA_11_VGPU_TYPE,
+ group='devices')
+
+ self.compute1 = self.start_compute_with_vgpu('host1')
+
+ def test_create_servers_with_vgpu(self):
+
+ # Create a single instance against a specific compute node.
+ self._create_server(
+ image_uuid='155d900f-4e14-4e4c-a73d-069cbf4541e6',
+ flavor_id=self.flavor, host=self.compute1.host,
+ networks='auto', expected_state='ACTIVE')
+
+ self.assert_mdev_usage(self.compute1, expected_amount=1)
+
+ self._create_server(
+ image_uuid='155d900f-4e14-4e4c-a73d-069cbf4541e6',
+ flavor_id=self.flavor, host=self.compute1.host,
+ networks='auto', expected_state='ACTIVE')
+
+ self.assert_mdev_usage(self.compute1, expected_amount=2)
diff --git a/nova/tests/unit/virt/libvirt/test_config.py b/nova/tests/unit/virt/libvirt/test_config.py
index 396edfd0248..c7577745ab4 100644
--- a/nova/tests/unit/virt/libvirt/test_config.py
+++ b/nova/tests/unit/virt/libvirt/test_config.py
@@ -3135,6 +3135,32 @@ def test_config_mdev_device(self):
config.LibvirtConfigNodeDeviceMdevInformation)
self.assertEqual("nvidia-11", obj.mdev_information.type)
self.assertEqual(12, obj.mdev_information.iommu_group)
+ self.assertIsNone(obj.mdev_information.uuid)
+
+ def test_config_mdev_device_uuid(self):
+ xmlin = """
+
+ mdev_b2107403_110c_45b0_af87_32cc91597b8a_0000_41_00_0
+ /sys/devices/pci0000:40/0000:40:03.1/0000:41:00.0/b2107403-110c-45b0-af87-32cc91597b8a
+ pci_0000_41_00_0
+
+ vfio_mdev
+
+
+
+ b2107403-110c-45b0-af87-32cc91597b8a
+
+
+ """
+
+ obj = config.LibvirtConfigNodeDevice()
+ obj.parse_str(xmlin)
+ self.assertIsInstance(obj.mdev_information,
+ config.LibvirtConfigNodeDeviceMdevInformation)
+ self.assertEqual("nvidia-442", obj.mdev_information.type)
+ self.assertEqual(57, obj.mdev_information.iommu_group)
+ self.assertEqual("b2107403-110c-45b0-af87-32cc91597b8a",
+ obj.mdev_information.uuid)
def test_config_vdpa_device(self):
xmlin = """
diff --git a/nova/virt/libvirt/config.py b/nova/virt/libvirt/config.py
index 1a81be3ade5..47e92e3ca91 100644
--- a/nova/virt/libvirt/config.py
+++ b/nova/virt/libvirt/config.py
@@ -3299,6 +3299,7 @@ def __init__(self, **kwargs):
root_name="capability", **kwargs)
self.type = None
self.iommu_group = None
+ self.uuid = None
def parse_dom(self, xmldoc):
super(LibvirtConfigNodeDeviceMdevInformation,
@@ -3308,6 +3309,8 @@ def parse_dom(self, xmldoc):
self.type = c.get('id')
if c.tag == "iommuGroup":
self.iommu_group = int(c.get('number'))
+ if c.tag == "uuid":
+ self.uuid = c.text
class LibvirtConfigNodeDeviceVpdCap(LibvirtConfigObject):
diff --git a/nova/virt/libvirt/driver.py b/nova/virt/libvirt/driver.py
index cc5e4b5da52..e792655a7de 100644
--- a/nova/virt/libvirt/driver.py
+++ b/nova/virt/libvirt/driver.py
@@ -8019,15 +8019,52 @@ def _get_mdev_capable_devices(self, types=None):
def _get_mediated_device_information(self, devname):
"""Returns a dict of a mediated device."""
- virtdev = self._host.device_lookup_by_name(devname)
+ # LP #1951656 - In Libvirt 7.7, the mdev name now includes the PCI
+ # address of the parent device (e.g. mdev__) due to
+ # the mdevctl allowing for multiple mediated devs having the same UUID
+ # defined (only one can be active at a time). Since the guest
+ # information doesn't have the parent ID, try to lookup which
+ # mediated device is available that matches the UUID. If multiple
+ # devices are found that match the UUID, then this is an error
+ # condition.
+ try:
+ virtdev = self._host.device_lookup_by_name(devname)
+ except libvirt.libvirtError as ex:
+ if ex.get_error_code() != libvirt.VIR_ERR_NO_NODE_DEVICE:
+ raise
+ mdevs = [dev for dev in self._host.list_mediated_devices()
+ if dev.startswith(devname)]
+ # If no matching devices are found, simply raise the original
+ # exception indicating that no devices are found.
+ if not mdevs:
+ raise
+ elif len(mdevs) > 1:
+ msg = ("The mediated device name %(devname)s refers to a UUID "
+ "that is present in multiple libvirt mediated devices. "
+ "Matching libvirt mediated devices are %(devices)s. "
+ "Mediated device UUIDs must be unique for Nova." %
+ {'devname': devname,
+ 'devices': ', '.join(mdevs)})
+ raise exception.InvalidLibvirtMdevConfig(reason=msg)
+
+ LOG.debug('Found requested device %s as %s. Using that.',
+ devname, mdevs[0])
+ virtdev = self._host.device_lookup_by_name(mdevs[0])
xmlstr = virtdev.XMLDesc(0)
cfgdev = vconfig.LibvirtConfigNodeDevice()
cfgdev.parse_str(xmlstr)
+ # Starting with Libvirt 7.3, the uuid information is available in the
+ # node device information. If its there, use that. Otherwise,
+ # fall back to the previous behavior of parsing the uuid from the
+ # devname.
+ if cfgdev.mdev_information.uuid:
+ mdev_uuid = cfgdev.mdev_information.uuid
+ else:
+ mdev_uuid = libvirt_utils.mdev_name2uuid(cfgdev.name)
device = {
"dev_id": cfgdev.name,
- # name is like mdev_00ead764_fdc0_46b6_8db9_2963f5c815b4
- "uuid": libvirt_utils.mdev_name2uuid(cfgdev.name),
+ "uuid": mdev_uuid,
# the physical GPU PCI device
"parent": cfgdev.parent,
"type": cfgdev.mdev_information.type,
diff --git a/nova/virt/libvirt/host.py b/nova/virt/libvirt/host.py
index 92f58e6899a..ebcc1125345 100644
--- a/nova/virt/libvirt/host.py
+++ b/nova/virt/libvirt/host.py
@@ -1503,7 +1503,7 @@ def list_mdev_capable_devices(self, flags=0):
def list_mediated_devices(self, flags=0):
"""Lookup mediated devices.
- :returns: a list of virNodeDevice instance
+ :returns: a list of strings with the name of the instance
"""
return self._list_devices("mdev", flags=flags)
diff --git a/nova/virt/libvirt/utils.py b/nova/virt/libvirt/utils.py
index 834f242c792..a1b9459b7e6 100644
--- a/nova/virt/libvirt/utils.py
+++ b/nova/virt/libvirt/utils.py
@@ -581,17 +581,31 @@ def get_default_machine_type(arch: str) -> ty.Optional[str]:
def mdev_name2uuid(mdev_name: str) -> str:
- """Convert an mdev name (of the form mdev_) to a
- uuid (of the form 8-4-4-4-12).
+ """Convert an mdev name (of the form mdev_ or
+ mdev__) to a uuid
+ (of the form 8-4-4-4-12).
+
+ :param mdev_name: the name of the mdev to parse the UUID from
+ :returns: string containing the uuid
"""
- return str(uuid.UUID(mdev_name[5:].replace('_', '-')))
+ mdev_uuid = mdev_name[5:].replace('_', '-')
+ # Unconditionnally remove the PCI address from the name
+ mdev_uuid = mdev_uuid[:36]
+ return str(uuid.UUID(mdev_uuid))
+
+def mdev_uuid2name(mdev_uuid: str, parent: str = None) -> str:
+ """Convert an mdev uuid (of the form 8-4-4-4-12) and optionally its parent
+ device to a name (of the form mdev_[_]).
-def mdev_uuid2name(mdev_uuid: str) -> str:
- """Convert an mdev uuid (of the form 8-4-4-4-12) to a name (of the form
- mdev_).
+ :param mdev_uuid: the uuid of the mediated device
+ :param parent: the parent device id for the mediated device
+ :returns: name of the mdev to reference in libvirt
"""
- return "mdev_" + mdev_uuid.replace('-', '_')
+ name = "mdev_" + mdev_uuid.replace('-', '_')
+ if parent and parent.startswith('pci_'):
+ name = name + parent[4:]
+ return name
def get_flags_by_flavor_specs(flavor: 'objects.Flavor') -> ty.Set[str]: